LONDON — British police said Friday they made two new “significant arrests” in their investigation into the radicalization of a middle-aged attacker accused of carrying out a deadly knife and vehicle rampage in the British capital.
Few details about the latest arrests were made public. But they reflected the widening effort to piece together a portrait of the 52-year-old suspect — from his upbringing around England, to his years of small-time crime and his emergence as Khalid Masood, the name he adopted along with other aliases.
In a glimpse into his final hours, a hotel manager in the seaside city of Brighton said Masood was laughing and talking about his family the night before the attack, and Britain’s Sky News reported that Masood was on a messaging app minutes before carving a deadly path over the Westminster Bridge as his car raced toward Parliament.
Mark Rowley, the acting deputy police commissioner, said two people have been arrested in the West Midlands and the northwest of England. That brought the number of people in custody to nine in connection with Wednesday’s attack, which killed three pedestrians and a police officer outside Parliament. Masood was shot and killed by security forces.
The “main line of our investigation is what led him to be radicalized. Was it through influences in our community? Influences from overseas? Or through online propaganda,” Rowley told reporters.
Police believe that Masood — who they say was born in Britain as Adrian Russell Ajao — acted alone, but they also were examining whether he had accomplices or had links with militant networks. The Islamic State claimed Masood was a “soldier” of its self-proclaimed caliphate, but the group often makes similar proclamations without providing any evidence of direct links to attackers.
“Our determination is to find out if either he acted totally alone, inspired by perhaps terrorist propaganda, or if others had encouraged, supported or directed him,” said Rowley.
As part of their inquiry, police said they have seized 2,700 items, including “massive” amounts of computer data.
“We need to get away from this lone-wolf thing,” Chris Phillips, former head of the national counterterrorism security office, told the BBC. “There’s almost always someone else involved.”
Meanwhile in Belgium, a man who drove a car carrying weapons at high speed in a pedestrian shopping street in Antwerp on Thursday — forcing people to jump out of the way — was charged with terrorism offenses. Federal prosecutors charged a man they identified only as Mohamed R., 39, with “attempted murder in a terror context.”
Belgian has been on elevated security alerts since suicide bombers attacked the Brussels airport and a subway station a year ago, killing 32 people. Memorial events to mark the anniversary were taking place across Belgium when the attack in London unfolded.
Rowley said at least 50 people were injured in the London attack, with 31 requiring medical treatment. Two people are still in critical condition and one has life-threatening injuries. London police identified the latest fatality as 75-year-old Leslie Rhodes from south London, who died of injuries late Thursday.
Details were still emerging about Masood, who was born on Christmas Day in 1964 in Kent in southeastern England. He later lived in cities including Luton and Birmingham.
It was unclear what he did professionally. According to the Sun tabloid, which said it saw a copy of Masood’s résumé, he worked as an English teacher in Saudi Arabia and then later back in England.
Former neighbors of Masood in Luton told broadcasters that he enjoyed gardening, and one thought he stayed at home and looked after his children. He had been investigated by intelligence services previously. But in a statement, Scotland Yard said Masood was not the subject of any current investigations and had not been convicted of any terrorism offenses before he unleashed Wednesday’s bloodshed.
Masood’s high school friends described him as a happy, soccer-loving teenager as a student at Huntleys, an all-boys’ school in southeastern England.
“I’m in deep shock … I knew him as Adrian Ajao,” Stuart Knight told The Washington Post.
“He was in my class at school for five years. He was a very nice lad, very sporty, very well liked by all the other students,” said Stuart, 52, who runs a butcher shop. “A fun guy to be around. He liked football and he played rugby. We raised some money for a new sports hall. We did a 24-hour sponsored football event together.”
He said the attack “certainly doesn’t relate the person I knew all those years ago.”
“His family were Christians. They went to a local Christian church. I don’t know if it [faith] was a big part of his life. It was a big part of his mother Janet’s life,” he said.
He said they lost touch after they left the school in 1981.
In Brighton, about 180 miles south of Masood’s home in Birmingham, the manager of the Preston Park hotel said Masood was “very friendly, laughing and joking” after checking in on Tuesday.
“He talked about his family, his mom, his dad his wife. He said his dad is ill, and his mom is upset because his dad is ill . . . I think he had one or two children,” Sabeur Toumi told Sky News.
Toumi said he asked Masood if he was in Brighton on holiday.
“He said, ‘No, I’m visiting friends in Brighton,’” said Toumi.
Sky also reported that Masood was on the popular messaging service WhatsApp just three minutes before turning his rented Hyundai into a killing machine on the bridge. Messages on the app are encrypted, and Sky did not have details of their contents.
British Prime Minister Theresa May said Masood was investigated by security services “some years ago . . . in relation to concerns about violent extremism.”
But she said that he was a “peripheral figure.”
“He was not part of the current intelligence picture. There was no prior intelligence of his intent or of the plot. Intensive investigations continue,” she said.
His last conviction was in December 2003 for possession of a knife.
Home Secretary Amber Rudd confirmed that Masood spent time in jail — not for terrorism offenses — prompting some to question whether he could have been radicalized in prison.
Scotland Yard said Masood was “known to police” and had a range of previous convictions for assaults, possession of offensive weapons and public-order offenses.
According to British media reports, on his final night he stayed at a budget hotel in Brighton, a seaside town in the south of England. The Sun said officers identified the hotel after finding a receipt left in the car that crashed into the railings of the Houses of Parliament.
A spokesman for the Enterprise rental car company confirmed reports that the Hyundai used in the attack came from one of its offices in Birmingham.
Police on Friday issued a public appeal for help. “There might well be people out there who did have concerns about Masood,” said Rowley.
Murphy reported from Washington.